III USOO5171349A United States Patent (19) 11 Patent Number: 5,171,349 Vetanovetz et al. 45) Date of Patent: Dec. 15, 1992

(54) SOLUBILITY COMPOUND 56) References Cited COMPOSITIONS U.S. PATENT DOCUMENTS 4,013,446 3/1977 Beresky et al...... 7/29 X (76) Inventors: Richard P. Vetanovetz, 435 4,507, 39 3/1985 Sullivan et al...... 7/29 X Beechwood St., Emmaus, Pa. 18049; Robert Peters, 2833 Pennsylvania St., FOREIGN PATENT DOCUMENTS Allentown, Pa. 18104 2072644A 10/1981 United Kingdom. OTHER PUBLICATIONS (21) Appl. No.: 690,099 Chemical Abstracts, vol. 93, 6001, Nr. 11, 1980, p. 622, 93:113193d "Solubilizing rocks using ', 22) Filed: Apr. 23, 1991 one page. Primary Examiner-Ferris Lander Attorney, Agent, or Firm-Caesar, Rivise, Bernstein, Related U.S. Application Data Cohen, & Pokotilow, Ltd. (63) Continuation-in-part of Ser. No. 648,644, Jan. 31, 1991, 57) ABSTRACT abandoned. Solid compound for dissolving into stock solutions advantageously employing urea phosphate as (51) Int. Cl...... CO5C 9/00 a phosphorous source. The use of urea phosphate makes (52) U.S. Cl...... 71/29; 71/30; it possible to have calcium present as well as nonche 71/64. lated trace metals without precipitation. (58) Field of Search ...... 71/29, 65, 30, 64.08, 71/64.1 13 Claims, No Drawings 5,171,349 1. 2 reaction products as ammonia-stabilized liquid compo SOLUBLITY COMPOUND FERTILIZER nents of fertilizers. Chemical Abstracts 106(3) 1013 liq COMPOSITIONS shows a liquid component for use in fertilizers which contains a urea phosphate polycondensation product. This is a continuation-in-part of U.S. Ser. No. 5 Chemical Abstracts 102(9)77486v also shows this. Other 07/648,644 filed Jan. 31, 1991, now abandoned. references of interest include Chemical Abstracts 101 (23)209498s which concerns the biological fate of BACKGROUND OF THE INVENTION urea/phosphate fertilizers; Chemical Abstracts 1. Field of the Invention 101 (21) 190398k which discusses the use of urea phos This invention concerns improved solid fertilizer O phate fertilizers; Chemical Abstracts 88(19)135558a compositions and in particular solid fertilizer composi which describes the reaction of that phosphoric acid tions useful for preparing aqueous fertilizer solutions for reacts with urea and with calcium salts; and Chemical precision plant nutrition. Abstracts 86(11)70783g which deals with the develop 2. Prior Art ment of liquid multicomponent fertilizers based on po In greenhouses, nurseries and other intensive horti 5 tassium and ammonium nitrates and diphosphates, urea, culture environments. best results are attained when water and trace elements. macro- and micronutrients are carefully delivered to the growing plants. Many growers choose to utilize com STATEMENT OF THE INVENTION pound high analysis water-soluble fertilizers. Typically, An improved solid fertilizer which dissolves com these fertilizers are marketed as solids which are dis 20 pletely in water to give a phosphorous-containing stock solved to prepare concentrated stock solutions which solution has now been found. This fertilizer is charac are then diluted into irrigation water by means of pro terized by being a solid, by having urea phosphate as the portioners or injection devices. principal phosphorous source, by containing calcium The Grace Sierra Horticultural Products Company and/or magnesium and/or nonchelated micronutrient markets a wide range of water-soluble solid compound 25 trace metals such as iron, manganese, copper, boron, fertilizer formulations under the Peters Professional (R) zinc and molybdenum, and by dissolving completely in trademark. These formulations are designed to dissolve water without precipitate formation initially or upon quickly and completely with no precipitation. It is also prolonged standing, such as for 24 hours or longer. desired that a fertilizer formulation have good long In one embodiment, this invention provides a calci term stability as a stock solution so as not to form pre 30 um-containing solid complex fertilizer which dissolves cipitates which can clog proportioners and irrigation completely in water to give a water-based precipitate lines. This has led to a limitation with water-soluble free stable aqueous stock solution, this solid fertilizer fertilizer formulation available heretofore. Calcium is containing solid urea phosphate as the principal phos an important nutrient which is called for in many plant phorous source and . nutrition formulations, but calcium salts cannot be used 35 In another embodiment, this invention provides a together with the conventional phosphorous sour trace metal-containing solid complex fertilizer which ces-monoammonium phosphate and diammonium dissolves completely in water to give a water-based phosphate-as the pHs which these phosphate sources precipitate free stable aqueous stock solution, this solid provide are too high (not acidic enough) to give ade fertilizer containing solid urea phosphate as the princi quate solubility to the calcium ions and thus give rise to pal phosphorous source and nonchelated micronutrient precipitation of the calcium salts in the stock solution trace metal nitrate or sulfate salts such as at least one of and in the proportioners. iron sulfate or nitrate, manganese sulfate or nitrate, Potassium phosphate or sodium phosphate can be copper sulfate or nitrate, and zinc sulfate or nitrate. This used as soluble phosphorous sources but these are either material may contain magnesium sulfate or nitrate, as expensive or not conducive to plant growth. Phos 45 well. It also may contain calcium nitrate. phoric acid can be used but is a liquid and hazardous to In addition, this invention provides a method for handle. Therefore, a grower wishing to fertilize with preparing a stable water-based phosphorous-containing both calcium and phosphorous, without resorting to the and calcium-containing fertilizer aqueous stock solu use of an alkali metal phosphate or liquid phosphorous tion. This method involves acid, will need to inject these two elements separately. 50 Obtaining a solid compound fertilizer admixture of urea Secondly, and similarly, the use of chelated trace phosphate as a primary phosphorous component and nutrients (micronutrients) has been widely postulated in calcium nitrate, and order to keep these trace nutrients in solution in stock Mixing this admixture with water at a ratio predeter solutions which also contain the monoammonium and mined to yield to a concentration of the admixture of diammonium . If nonchelated micronutrients 55 2 to 40% by weight and allowing the admixture to (such as simple nitrates or sulfates) are employed with dissolve completely. the conventional phosphorous sources, the micronutri This same general process can be used to prepare a ents tend to precipitate from solution. Again, these nonchelated trace metal (e.g. FeSO4, etc.)-containing chelated micronutrients increase the cost of the fertil phosphorous-containing fertilizer aqueous stock solu izer formulations. tion, which also constitutes an aspect of this invention. The present invention employs urea phosphate in The inclusion of urea phosphate in a dry blended water-soluble solid fertilizer formulations. Urea phos mixture of nutrient sources which include calcium, phate is a known material. The text, Urea and Urea and/or magnesium with or without trace metals such as Phosphate Fertilizers by Clifford W. Fowler (Noyes iron and the like in nonchelated forms such as nitrates Data Corporation, Park Ridge, N.J., 1976) at page 23, 65 and/or sulfates offers several advantages. For one, the shows a process for preparing this material and suggests urea phosphate establishes a low pH condition when the that it may be used as a fertilizer. Similarly, U.S. Pat. blended mixture is added to water to make a concen No. 4,456,463 discloses the use of urea-phosphoric acid trated stock solution. A stock solution pH in the range 5,171,349 3 4. of 0 to 2 may be achieved. This low solution pH main % w N) of from 1% to 40% and potassium contents (as tains solubility and clarity of the concentrated stock % w K2O) of from 0% to 35%. Within these formula solution. Urea phosphate, by the effect it has on solution tion ranges and parameters, it is desirable for the urea pH, prevents the formation of calcium phosphate, mag phosphate to be the primary or principal source of phos nesium phosphate and iron phosphate, which are not 5 soluble. Similarly, the low pH helps prevent calcium phorous in the present solid fertilizers. By "primary" or from precipitating in the presence of sulfate ions which "principal" source is meant that urea phosphate contrib may be present. Therefore, when urea phosphate is used utes at least about 50%, and preferably at least about as a primary phosphorous source, it will make possible 95% and especially essentially 100% of the phospho the inclusion of phosphorous and a metal such as cal rous present in these products. In cases where urea cium, magnesium or iron in one compound fertilizer, 10 phosphate is not the sole phosphorus source, other without the use of chelates or the disadvantage of a phosphates such as potassium phosphate and ammo precipitate forming. This allows the end user to prepare nium phosphate can make up the balance. and apply a complete nutrient solution using one stock In addition to the phosphorous and nitrogen and solution and utilizing one injector. It also makes possi optional potassium, the materials of this invention in ble the inclusion of nonchelated trace nutrients into 15 clude calcium and/or at least one metal selected from phosphorous-containing nutrient solutions without pre magnesium, iron, manganese, copper, boron, zinc and cipitation. It also allows the fertilizer solution to have molybdenum. Ranges of concentration for these materi an increased acidifying effect on the growing medium if als are as follows: needed. In summary, the advantages of using urea phos phate as a primary phosphate source in a solid com 20 pound fertilizer are: Concentration Range as a. The ability to purchase, prepare and apply a complete Elemental Nutrient in nutrient solution with one stock solution and one Nutrient Final Dry Product, % proportioner. Ca 0-15 25 Mg 0-5.0 b. The ability to use nonchelated micronutrient trace Fe 0-1.0 elements without reduction in solubility in the stock Mn 0-1.0 solution as is observed using conventional dry phos Cu 0-0.5 phorus sources. B 0-0.5 c. The ability to formulate acidic fertilizers that are sold Zn 0-0 as dry solids and thus are less hazardous to the end 30 Mo 0-0.2 user than liquid phosphoric acid-based materials. Importantly, these materials are not provided as che DETALED DESCRIPTION OF THE lates, such as EDTA chelates or the like, but rather as INVENTION simple salts, especially nitrates or sulfates. In the case of The fertilizer compositions of this invention are dry 35 boron, it may be supplied as boric acid. Molybdenum solid materials. This is defined to mean that they are may be provided as an alkali metal or ammonium mo particulate flowing solids having a water content of less lybdate. Magnesium, although often present in higher than about 10% by weight total composition. concentration than typically associated with "trace The fertilizer compositions of this invention contain metals' can be present as magnesium sulfate or nitrate. urea phosphate This means that the following representative materials may be used in the products with minimal concern (NH-i-NH"hypo about precipitation or the like: calcium nitrate, magne O sium sulfate, , ferrous sulfate, ferrous 45 nitrate, manganese sulfate, manganese nitrate, cupric as a dry particulate solid. This amount of urea phos sulfate, cupric nitrate, boric acid, zinc sulfate, zinc ni phate will vary depending upon the nitrogen and phos trate, sodium molybdate, ammonium molybdate and the phorous analysis desired for the formulated composi like. In addition, the solid products can contain addi tion. Typically, the urea phosphate is used in place of tional materials such as cofactors if desired. monoammonium phosphate or diammonium phosphate. SO These materials are mixed as solids, often with minor Since urea phosphate contributes nitrogen as well as amounts of water as hydration and the like being pres phosphorous in a precise stoichiometric ratio to the dry ent to allow a homogenous product to be formed. The fertilizer mix, it may be necessary to add additional resulting products are dry solids as that term has been phosphorous sources or nitrates or urea as additional defined herein. They can be sold in bulk or they can be nitrogen sources to alter the ratio provided by urea 55 premeasured into units suitable for forming a standard phosphate alone. A solid product of the invention will volume of stock solution. In either case, it is often of contain at least about 5% by weight (total solids) of urea advantage to distribute the materials in water-resistant phosphate which by itself will contribute about 2.5% w packaging to minimize caking and lumping. Similarly, it phosphorous, (calculated as POs) and about 1% w my be of advantage to include soluble inerts which are nitrogen as N. The solid product can contain up to dyes, or which promote dispersion, prevent caking, or about 95% by weight of urea phosphate which would the like. by itself contribute about 43% w phosphorous as P2O5 The solid products of this invention are made up into and about 17% w nitrogen as N. Higher P or Nassays stock solutions by dissolving in water. This should be can be achieved by the addition of phosphorus sources carried out in clean equipment usually with some agita or various nitrogen sources, such as urea or ammonium 65 tion. Commonly, the stock solution contains from about nitrate. The range of materials falling within the scope 0.5 to about 5 lbs/gallon of dissolved solid (that is, from of this invention have phosphorous contents (as % w about 2% to about 40% by weight of dissolved solid). P2O5) of from about 2.5% to 44%, nitrogen contents (as Preferably, the stock solution contains from about 5% 5,171,349 5 6 to about 35% by weight of dissolved solid. This stock TABLE ll-continued solution material is diluted by a factor of from 10 to 200 EFFECT OF UPON ELIMINATING PRECIPITATION for application to the plants. This gives final concentra AS COMPARED TO MAP WHEN MIXED WITH tions which, for nitrogen, range from about 25 ppm up Ca(NO3)2. Mg(NO3)2 AND/OR METAL SULFATES to about 450 ppm, with the other nutrients scaled ac Precipitate Occurred No Precipitate Occurred cordingly. of zinc sulfate/liter 0.5 gr of zinc sulfate/liter The materials of this invention will be further de "One gram of UP was added to Ca(NO3)2 where Ca(NO3) was added at 100, 200, scribed with reference to the following examples. These 300, 400, 500, 600, 700, 800,900 and 1000 grams per liter of solution and no precipi tate occurred in any of the solutions. are provided to illustrate the practice of the invention O and not to limit its scope which is defined by the ap These results show that one can provide solid com pended claims. pound fertilizers which can be successfully formed into EXAMPLES stable stock solutions having weight compositions as follows: Eight pairs of typical stock solutions were prepared 15 using various combinations of nutrient sources, and the results differed depending on the source of phosphate. Preferably The nutrient sources included materials which are com A. Calcium/phosphorous compound fertilizer monly used in the manufacture of water-soluble fertiliz Calcium Nitrate 0.1 to 99% 5 to 95% ers. The most widely used source of phosphorous is 20 Urea Phosphate 0.1 to 99% S to 95% Other Fertilizer 0 to 75% 0 to 75% monoammonium phosphate (MAP) which was com Materials pared with urea phosphate (UP) to determine differ B. Calcium/phosphorous/micronutrient compound fertilizer ences in their effects on maintaining the solubility of all Calcium Nitrate to 99% S to 94% components of various compound fertilizer mixtures. In Urea Phosphate 1 to 99% S to 94% each pair, one was based on UP and the other on MAP. 25 Trace Metal Sulfates 0.1 to 50% 1 to 40% Some precipitates occurred in the MAP-based materials and Nitrates especially within the first 24 hours and after 30 days, the data in including FeSO4 2 to 40% Table i were assembled. CuSO4. Conclusion 30 Other Fertilizer 0 to 75% 0 to 75% Materials including These results show that the use of monoammonium Mg(NO3)2 and MgSO4 phosphate (MAP) in mixtures with calcium nitrate, C. Phosphorous/micronutrient compound fertilizer - magnesium nitrate, ferrous sulfate, manganese sulfate, Urea Phosphate to 99% 5 to 98% copper sulfate and zinc sulfate does not maintain the Trace Metal Sulfates 0.1 to S0% to 40% 35 and Nitrates including solubility of these components in solution. This is in FeSO4 contrast to the use of urea phosphate (UP) which does MnSO4 maintain the solubility of these in solution consisting of ZnSO4 these water soluble nutrient sources. These data show CuSO4. Other Fertilizer O to 75% O to 75% that the use of UP will permit calcium nitrate, magne 40 Materials including sium nitrate and/or metal sulfates to be present in clear, Mg(NO3)2 and MgSO4 concentrated stock solutions. This is a result that MAP, as a phosphorus source, is incapable of providing. What is claimed is: TABLE 1. 1. A precipitate free concentrated aqueous stock solu EFFECT OF UP ON ELIMINATING PRECIPITATION tion formed from a dry solid fertilizer mixture and con AS COMPARED TO MAP WHEN MIXED WITH taining from about 2% to 40% by weight of dissolved Ca(NO3)2. Mg(NO3)2 AND/OR METAL SULFATES solid fertilizer, said stock solution containing phospho Precipitate Occurred No Precipitate Occurred rous and calcium, said stock solution being prepared by A. l. gr of MAP -- 100gr of 1 gr of UP + 100 gr of 50 bringing together said dry solid fertilizer mixture and calcium nitrate/liter calcium nitrate/liter water to make up a concentrated stock solution, said B. 10 gr of MAP + 10 gr of 10gr of UP + 10 gr of calcium nitrate/liter calcium nitrate/liter dry solid fertilizer mixture comprising 5% to 95% by C. 100 gr of MAP + 100 gr of 100 gr of UP + 100 gr weight of dry urea phosphate as the principal phospho calcium nitrate/liter of calcium nitrate/liter rous source and 5% to 95% by weight of dry calcium D. 10 gr of MAP + 10 gr of 10gr of UP + 10gr of 55 nitrate to contribute a desired amount of phosphorous ferrous sulfate/liter ferrous sulfate/liter E. 100 gr of MAP + 100 gr of 100 gr of UP + 100 gr and calcium for fertilization purposes. ferrous sulfate/liter of ferrous sulfate/liter 2. The concentrated stock solution of claim 1 addi F. 150 gr of MAP + 150 gr of 150gr of UP + 150 gr tionally comprising at least one nonchelated trace metal calcium nitrate -- 150 gr of calcium nitrate + 150 gr salt selected from the group consisting of iron, magne of magnesium nitrate/liter of magnesium nitrate/liter sium manganese, copper and zinc sulfates, chlorides and G. : 100 gr of MAP + 100 gr of 100 gr of UP + 100 gr of nitrates. ferrous sulfate -- 30 gr ferrous sulfate + 30 gr of manganese sulfate + 10 gr of manganese sulfate + 10 gr 3. The concentrated stock solution of claim 1 wherein of copper sulfate - 40 gr of copper sulfate + 40 gr the nonchelated trace metal salt is present in an amount of zinc sulfate/liter of zinc sulfate/liter up to 50% by weight of the total fertilizer. H. 50 gr of MAP + 95 gr of 50 gr of UP + 95 gr of 65 4. The concentrated stock solution of claim 1 addi calcium nitrate -- 1.0 gr calcium nitrate -- 1.0 gr of ferrous sulfate -- 0.5 gr of ferrous sulfate -- 0.5 gr tionally comprising a nonchelated magnesium salt se of manganese sulfate + 0.25 gr of manganese sulfate -- lected from the group consisting of magnesium sulfate of copper sulfate + 0.5 gr 0.25 gr of copper sulfate + and magnesium nitrate and chloride. 5,171,349 7 8 5. The concentrated stock solution of claim 4 wherein 11. The concentrated stock solution of claim 6 addi the nonchelated magnesium salt is present in an amount tionally comprising magnesium sulfate or nitrate. up to 50% by weight of the total complex fertilizer. 12. A precipitate free concentrated aqueous stock 6. The concentrated stock solution of claim 1 com solution formed from a dry solid fertilizer mixture and prising 5 to 94% by weight of urea phosphate, 5 to 94% containing from about 2% to 40% by weight of dis by weight of calcium nitrate, and 0.1 to 50% by weight solved solid fertilizer, said stock solution containing of nonchelated micronutrient trace metal salt. phosphorous and a micronutrient trace metal salt, said 7. The concentrated stock solution of claim 6 wherein stock solution being prepared by bringing together said the nonchelated micronutrient trace metal salt com dry solid fertilizer mixture and water to make up a prises ferrous sulfate or nitrate. 10 concentrated solution, said dry solid fertilizer mixture 8. The concentrated stock solution of claim 6 wherein comprising 5% to 95% by weight of dry urea phosphate the nonchelated micronutrient trace metal salt com as the principal phosphorous source and 5% to 95% by prises copper sulfate or nitrate. weight of a micronutrient trace metal salt selected from 9. The concentrated stock solution of claim 6 wherein the group consisting of calcium, iron, magnesium, man the nonchelated micronutrient trace metal salt com 15 ganese, boron and molybdenum; and copper and zinc prises manganese sulfate or nitrate. sulfates, chlorides and nitrates. 10. The concentrated stock solution of claim 6 13. The concentrated stock solution of claim 12 wherein the nonchelated micronutrient trace metal salt wherein said calcium is calcium nitrate. comprises zinc sulfate or nitrate. k k 20

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